Department of Botany, University of Karachi, Karachi.
Annual or perennial herbs or rarely undershrubs, with glands at least on the young parts. Leaves simple, exstipulate, opposite or the uppermost sometimes alternate. Inflorescence of solitary, axillary flowers, rarely few flowered raceme or fascicles. Flowers bisexual, zygomorphic, mostly hypogynous and generally with characteristic glands at the base of the stalk. Sepals 5 (rarely 4), connate basally. Corolla broadly tubular or obliquely campanulate, 5-lobed, bilabiate. Stamens 4 (rarely 2), free, epipetalous, didynamous; the fifth (posterior) represented by a small staminode; connective usually gland tipped. Disc usually conspicuous, regular, fleshy. Carpels 2, syncarpous; ovary bilocular or tetralocular due to false septum, superior; placentation axile; ovules 1-numerous per locule; style 1 with 2 stigmas (rarely 4-lobed). Fruit loculicidal capsule or nut, often with hooked spines, prickles or wings. Seeds smooth, albuminous, embryo small and straight.
A family with 12 genera and about 50 species, mostly maritime or desert plants of Old World tropics and subtropics. It is represented by 2 genera and 2 species in W. Pakistan including 1 cultivated species.
Acknowledgement: We are grateful to the United States Department of Agriculture for financing this research under P.L. 480.